IMAGE FORMING APPARATUS, IMAGE FORMING METHOD AND COMPUTER-READABLE STORAGE MEDIUM

Methods and apparatuses for forming images on recording media of different sizes are provided. The image forming procedure may include reading setting information which includes the size of a substitute recording medium from a storage and, when the size of the recording medium specified by the print instruction is not available, executing a print instruction by automatically changing the size of a recording medium to be used to the size of the substitute recording medium based on the setting information. The image forming procedure may further include invalidating the setting information with respect to second and subsequent pages of the recording medium of identical size during one print job. Additional computer-readable storage media storing image forming procedures are also provided.